Bis(4-hydroxy-3,5-dialkylbenzyl)cyano-carboxylic acid esters

ABSTRACT

The reaction of one mole of a Mannich base corresponding to the formula ##SPC1## 
     And one mole of a Mannich base corresponding to the formula ##SPC2## 
     Wherein R 1 , R 2 , R 4  and R 5  are independently selected from alkyl groups having 1 to 6 carbon atoms and R is alkyl, preferably lower alkyl, with 1 mole of a carboxylic acid ester corresponding to the formula R 3  CH 2  COOR 4  wherein R 3  is --H, --CN or --COOR 4  and R 4  is an alkyl, thioether, oxyether or aralkyl group having up to 20 carbons in the presence of a catalytically effective amount of an alkaline catalyst is useful for preparing compounds corresponding to the formula ##SPC3## 
     The compounds represented by the above formula are useful as stabilizers for synthetic resins, particularly polyolefins. Compounds of the above formula, when R 3  is --CN are novel and may also be prepared by reacting 1 mole of ##SPC4## 
     And 1 mole of ##SPC5## 
     Wherein X is halogen with 1 mole of NCCH 2  COOR 4  in the presence of an alkali metal and an anhydrous inert organic solvent.

This application is a division of application Ser. No. 211,125 filed Dec. 22, 1971 now U.S. Pat. No. 3,856,846, which application in turn was a continuation-in-part of application Ser. No. 714.100, filed Mar. 18, 1968 now U.S. Pat. No. 3,646,110.

This invention relates to a novel process of preparing dialkyl benzyl carboxylic esters, certain novel compounds and resins stabilized therewith.

Esters of the formula ##SPC6##

Wherein R₁, R₂, R₅ and R₆ are the same or different linear or branched alkyl groups having 1 to 6 carbon atoms, R₃ is --H, --CN, or --COOR₄, and R₄ is a linear, branched, cyclic, saturated or unsaturated alkyl, thioether, ether, or aralkyl group, having 1 to 20 carbon atoms can be prepared by reacting in an inert organic solvent one mole of a Mannich base of the formula ##SPC7##

And one mole of a Mannich base of the formula ##SPC8##

Wherein R₁, R₂ , R₅ and R₆ are as defined above with one mole of a carboxylic acid ester of the formula R₃ -CH₂ -COOR₄, wherein R₃ and R₄ are as defined above and R is preferably lower alkyl in the presence of a catalytic amount of an alkaline compound selected from alkali metal compounds and alkaline earth metal compounds. When R₁ is the same as R₅ and R₂ is the same as R₆, the reaction may be conducted in a single step by reacting two moles of the Mannich base with one mole of the carboxylic acid ester. Suitable alkaline compounds include the oxides, hydroxides, amides, hydrides and alcoholates of alkali and alkaline earth metals such as, lithium, sodium, potassium, calcium, magnesium and barium. Specific examples of suitable compounds include lithium, sodium and barium oxides; sodium, potassium, calcium, magnesium and barium hydroxides; sodium, lithium, calcium, magnesium, and barium hydrides; sodium amide, sodium acetamide, lithium amide and magnesium amide; and sodium methylate, sodium ethylate, sodium propylate, sodium phenate, potassium phenate, calcium ethylate, magnesium methylate, magnesium ethylate and barium ethylate as well as mixtures thereof.

The Mannich bases react almost quantitatively with the carboxylic acid esters and the Mannich bases are readily prepared by the well known reaction of phenols, formaldehyde, and secondary amines, such as dimethylamine. Therefore, this process of the present invention provides a very economic procedure.

A preferred method for the preparation of symmetrical bis-products from Mannich bases consists in refluxing two moles of a Mannich base when R₁ is the same as R₅ and R₂ is the same as R₆ with 1 mole of carboxylic acid ester (malonic acid ester, cyanoacetic acid ester) at 60° to 250°C. in the presence of 1 to 20 g of an alkali metal or alkaline earth metal alcoholate in a suitable solvent, e.g., in 1 liter of toluene, under nitrogen for 1/2 to 4 hours. When the reaction is terminated, the reaction mixture is cooled and the reaction product is recovered. For this purpose, the catalyst is first removed, e.g., by neutralization with dilute acid and shaking out with water, and then the reaction solution is dried. The solvent is distilled off under reduced pressure and the residue may be purified by recrystallization. The yield is generally about 80 to 99 percent.

In the preparation of the asymmetrical bis-products, which are particularly effective stabilizers, one mole of carboxylic acid ester is reacted with one mole of a Mannich base according to the following equation to form an intermediate compound ##SPC9## This compound is then further reacted with one mole of a Mannich base having different alkyl group than the first Mannich base to form the product. Both reactions can be carried out in the same reaction vessel similar to the procedure described above for the preparation of the symmetrical compounds. In the case of the asymmetrical compounds, the two Mannich bases are added to the reaction vessel successively for refluxing whereby the second Mannich base is generally added about 2 hours after the first base.

The reaction here involved is a "C-alkylation" of the phenol Mannich bases to disubstituted malonic acid or cyanoacetic acid esters. The literature indicated that such C-alkylation would be possible only when the difficulty available ammonium salts of the phenol-Mannich base are used as starting material (see H. Hellmann and G. Opitz, "α-Aminoalkylation", 1960, p. 284). It was not to be expected that the reaction described herein would be possible and would smoothly produce the novel malonic and cyanoacetic esters of the phenol Mannich bases.

The bis-(4-hydroxy-3,5-dialkyl-benzyl) mono-carboxylic ester compounds of formula I, wherein R₃ = H, are obtained by saponification and decarboxylation of the corresponding cyanoacetic or malonic acid esters.

Compounds of the formula ##SPC10##

wherein R₁, R₂, R₄, R₅ and R₆ are as defined above are novel. These compounds may be prepared by the novel process described above or can be prepared by reacting, in the presence of an anhydrous inert organic solvent and an alkali metal, 1 mole of ##SPC11##

wherein X is halogen with 1 mole of cyanocarboxylic acid ester of the formula NCCH₂ COOR₄.

Anhydrous inert solvents which are suitable include aromatic hydrocarbons, aliphatic hydrocarbons, glycol ethers, other high boiling ethers and alcohols of the formula R₄ OH, wherein R₄ is as defined hereinabove. Aromatic hydrocarbons are the preferred solvents.

Suitable alkali metals include lithium, sodium and potassium and sodium is especially preferred.

The following examples are given to illustrate the invention but not to limit the scope of the invention.

EXAMPLE 1 Preparation of Bis-(4-Hydroxy-3,5-Di-Tert. Butyl 4-Hydroxybenzyl) Cyanoacetic Acid Ethyl Ester.

A. 263.4 G (1 mole) of (4-hydroxy-3,5-di-tert.butylbenzyl) dimethylamine, 51 g (0.45 moles) of cyanoacetic acid ethylester, 3 g of magnesium ethylate, and 5 g of sodium methylate were refluxed in 1 liter of absolute alcohol for 1.5 hours; after cooling, the precipitated reaction product was filtered. The reaction product was shaken out with 96% alcohol and once recrystallized from 1.5 liter of acetone.

Yield: 255 g (99% of theory): M 212°-213°C. Analysis: found: C, 76.3%; H, 9.13%; calc. C, 76.3%; H, 9.35%.

B. 300 G (1mole) of 3,5-di-tert-butyl-4-hydroxy-benzyl bromide and 56 g (0.5 moles) of cyanoacetic acid ethyl ester in 500 CC of petroleum ether were added to a suspension of 23 g (1 g atom) of sodium in 1600 CC of petroleum ether with stirring and the mixture was refluxed for about 3 hours.

The reaction solution was then washed with water and dried. The solvent was evaporated under vacuum and the product was recrystallized from petroleum ether.

EXAMPLE 2 Preparation of Bis-(4-Hydroxy-3-Methyl-5-Tert. Butylbenzyl) Malonic Acid Distearyl Ester

(Stabilizer I)

27.6 G (0.125 mole) of (4-hydroxy-3-methyl-5-tert. butylbenzyl) dimethylamine, 30.5 g (0.05 mole) of malonic acid distearyl ester, and 0.5 g of sodium methylate were refluxed in 100 cc of absolute toluene for 21/2 hours while a current of nitrogen was passed through the reaction mixture. After cooling, the reaction mixture was diluted with methylene chloride, shaken out with 2N hydrochloric acid and water, and evaporated to dryness. The residue was slurried in methanol, filtered, and washed.

Yield: 41 g (85% of theory): m 83°-90°C. Analysis: calc.: C, 78.69%; H, 11.32%; 0, 9.98%. Found: C, 79.25%; H, 10.66%; 0, 9.99%.

This reaction also proceeds as described above with substantially the same yields if hydroxides such as sodium or potassium hydroxide; hydrides such as lithium, calcium or magnesium hydride or amides such as sodium or magnesium amide are used instead of the alcoholate.

EXAMPLE 3 Preparation of 1-(3-Methyl-5-Tert.Butyl-4-Hydroxyphenyl)-3-(3,5-Di-Isopropyl-4-Hydroxyphenyl)-2,2-Bis-Carbostearoxy Propane

4.4G (0.02 mole) of (4-hydroxy-3-methyl-5-tert.butylbenzyl)-dimethylamine, 12.2 g (0.02 mole) of malonic acid distearyl ester, and 0.2 g of sodium methylate in 100 cc of absolute xylene were refluxed under nitrogen for 2 hours. Subsequently, 5 g (0.213 moles) of (4-hydroxy-3,5-diisopropylbenzyl)-dimethylamine were added, and the mixture was again refluxed for 11/2 hours. After cooling, the reaction mixture was shaken out first with 2N hydrochloric acid, then with water, dried, and the solvent was evaporated in vacuo. After recrystallization from an isopropanol-methanol mixture, there were obtained 16 g (82% of theory) of the reaction product, m 90°-93°C.

Analysis: Calc.: C, 78.79%; H, 11.37%; 0, 9.84%. Found: C, 78.72%; H, 11.09%; 0, 9.90%.

EXAMPLE 4 Preparation of Bis-(3,5-Di-Tert.Butyl-4-Hydroxybenzyl)-Malonic Acid-Di-(3-HexylMercapto)-Propylester

(Stabilizer II)

By reaction of the Mannich base of 2,6-di-tert.butylphenol with malonic acid di(3-hexyl-mercapto) propyl ester, 23 g (0.055 mole) of malonic acid di(3-hexylmercapto) propyl ester, 32.8 g (0.125 mole) of the Mannich base of 2,5-ditertiary butylphenol, and 0.5 g of sodium methylate were refluxed in 100 cc of absolute toluene for 1.5 hours, and, after cooling, washed with 2N hydrochloric acid, dried and concentrated to dryness. The residue was twice recrystallized from petrol ether.

Yield: 36.9 g = 80% of theory. Analysis: calc.: C, 73.08%; H, 7.82%; 0, 11.45%; S, 7.65%. Found: C, 72.76%; H, 8.03%; 0, 11.22%; S, 7.47%. M.P. 84°-86°C.

Some of the compounds prepared in an analogous manner, are: bis-(3,5-di-tert.butyl-4-hydroxybenzyl) malonic acid di(3-laurylmercapto) propyl ester (Stabilizer III); m 71°-73°C; yield 70%; α-(4-hydroxy-3,5-di-tert.butylbenzyl)-α'-(4-hydroxy-3-tert.butyl-5-methylbenzyl)-malonic acid distearyl ester (Stabilizer IV) m 87°-90°C; yield 81%.

Examples of other compounds which are prepared in the same way are listed in Table I, where they are defined by their substituents according to formula I. Their structure, can be determined, by their molecularweight, IR spectra, and quantitative analysis. The melting points of some specific compounds are also given in degrees C. under the column M.P. Those compounds in which the R₄ group is followed by a number in parenthesis are used in tests of other examples and are identified by this number.

                                      TABLE I                                      __________________________________________________________________________     R.sub.1                                                                             R.sub.2                                                                             R.sub.5                                                                             R.sub.6                                                                             R.sub.3                                                                              R.sub.4      M.P.                                    __________________________________________________________________________     --CH.sub.3                                                                          --CH.sub.3                                                                          --CH.sub.3                                                                          --CH.sub.3                                                                          --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.5                                                                           197-199                                 "    "    "    "    --COOR.sub.4                                                                         "            190-192                                 "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                 CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.12 H.sub.25                                  "    "    "    "    --COOR.sub.4                                                                         "            78                                      "    "    "    "    --CN  --C.sub.20 H.sub.41                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.18 H.sub.37                                  "    "    "    "    --COOR.sub.4                                                                         "            90                                      "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    CH.sub.3                                                                            CH.sub.3                                                                            t.butyl                                                                             t.butyl                                                                             --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "            146                                     "    "    "    "    --CN  --C.sub.2 H.sub.5                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          t.butyl                                                                             t.butyl                                                                             i.propyl                                                                            i.propyl                                                                            --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    i.propyl                                                                            i.propyl                                                                            "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                   CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.12 H.sub.25                                                                         166-168                                 CH.sub.3                                                                            CH.sub.3                                                                            t.butyl                                                                             t.butyl                                                                             --COOR.sub.4                                                                         "            82                                      "    "    "    "    --CN  --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    i.propyl                                                                            i.propyl                                                                            i.propyl                                                                            i.propyl                                                                            --CN  --C.sub.18 H.sub.37                                  "    "    "    "    --COOR.sub.4                                                                         "            103-104                                 "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    --CH.sub.3                                                                          t.butyl                                                                             t.butyl                                                                             t.butyl                                                                             --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.5                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                 CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    -- CN --C.sub.12 H.sub.25                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.18 H.sub.37                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.20 H.sub.41                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    --CH.sub.3                                                                          --CH.sub.3                                                                          "    --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.5                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    -- CN --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                 CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.12 H.sub.25                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.20 H.sub.41                                  "    "    "    "    -- COOR.sub.4                                                                        "                                                    "    "    "    "    --CN  --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.18 H.sub.37                                  "    "    "    "    --COOR.sub.4                                                                         "            100                                     "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    CH.sub.3                                                                            t.butyl                                                                             CH.sub.3                                                                            "    --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.5 (6)                                                                       181-182                                 "    "    "    "    --COOR.sub.4                                                                         "            174-175                                 "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "            128-130                                 "    "    "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    -- COOR.sub.4                                                                        "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.20 H.sub.41                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "            95-97                                   "    "    "    "    --CN  --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "  (11)      98-99                                   "    "    "    "    --CN  --CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                 CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.12 H.sub.25 (8)                                                                     104-105                                 "    "    "    "    --COOR.sub.4                                                                         "            88-89                                   "    "    "    "    -- CN --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.18 H.sub.37                                                                         72-75                                   "    "    "    "    --COOR.sub.4                                                                         "  (I)       83-90                                   "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                               "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    t.butyl                                                                             "    t.butyl                                                                             "    --CN  --CH.sub.3                                           "    "    "    "    --COOR.sub.4                                                                         "            170-171                                 "    "    "    "    --CN  --C.sub.2 H.sub.5 (7)                                                                       211-212                                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 (CH.sub.3).sub.2                          "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.9                                    "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C(CH.sub.3).sub.3                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 CH(CH.sub.3).sub.2                        "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --CH.sub.2 --CH=CH.sub.2                             "    "    "    "    --COOR.sub.4                                                                         "            135-137                                 "    "    "    "    --CN  --C.sub.6 H.sub.13                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.17                                   "    "    "    "    --COOR.sub.4                                                                         "   (12)     104-105                                 "    "    "    "    --CN  --CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3                                 CH.sub.3                                             "    "    "    "    --COOR.sub.4                                                                         "  (13)      114                                     "    "    "    "    --CN  --C.sub.12 H.sub.25 (9)                                                                     119-120                                 "    "    "    "    --COOR.sub.4                                                                         "  (14)      112-113                                 "    "    "    "    --CN  --C.sub.16 H.sub.33                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.18 H.sub.37                                                                         95-96                                   "    "    "    "    --COOR.sub.4                                                                         "            98-100                                  "    "    "    "    --CN  --C.sub.20 H.sub.41                                  "    "    "    "    --COOR.sub.4                                                                         "            93                                      "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "            160                                     "    "    "    "    --CN                                                       "    "    "    "    --COOR.sub.4                                                                         "            131-132                                 "    "    "    "    --CN  --CH.sub.2 CH.sub.2                                  "    "    "    "    --COOR.sub.4                                                                         "                                                    --CH.sub.3                                                                          --CH.sub.3                                                                          --CH.sub.3                                                                          --CH.sub.3                                                                          --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "  (20)      68                                      "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.4 SC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.8 SC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 SC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    T.butyl                                                                             T.butyl                                                                             T.butyl                                                                             T.butyl                                                                             --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "            118-119                                 "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "            88-89                                   "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "            98-100                                  "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "  (21)      80                                      "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "  (22)      72-75                                   "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "  (II)      84-86                                   "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "  (23)      82-84                                   "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "  (III)     78-79                                   "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "  (24)      72-75                                   "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub. 2 H.sub.4 SC.sub.2                                   H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.8 SC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 SC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    --CH.sub.3                                                                          t.butyl                                                                             --CH.sub.3                                                                          t.butyl                                                                             --CN  13 C.sub.2 H.sub.4 SC.sub.2 H.sub.5                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH(CH.sub. 3).sub.2               "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "            76-77                                   "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.12 H.sub.25                                                        57-58                                   "    "    "    "    --COOR.sub.4                                                                         "            < 50                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SCH.sub.3                          "    "    "    "    --COOR.sub.4                                                                         "            135-136                                 "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "            78-80                                   "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.16 H.sub.33                                                        57-58                                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.4 SC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.8 SC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 SC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    t.butyl                                                                             "    --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 SC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 SC.sub.2 H.sub.4 SC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 SC.sub.4 H.sub.8 SC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 SC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.8 OC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 OC.sub.8 H.sub.17                 "    "    "    "    -- COOR.sub.4                                                                        "                                                    "    --CH.sub.3                                                                          --CH.sub.3                                                                          --CH.sub.3                                                                          --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.12 H.sub.25                 "    "    "    "    -- COOR.sub.4                                                                        "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.8 OC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 OC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    t.butyl                                                                             "    t.butyl                                                                             --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "  (17)      105°C                            "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.8 OC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 OC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    t.butyl                                                                             "    t.butyl                                                                             "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.5                   "    "    "    "    --COOR.sub.4                                                                         "  (15)      119-121                                 "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH(CH.sub.3).sub.2                "    "    "    "    --COOR.sub.4                                                                         "  (16)      101-103                                 "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "  (18)      94                                      "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.6 H.sub.13                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OCH.sub.2 CH(C.sub.2 H.sub.5)-                               -                                                                              (CH.sub.2).sub.3 CH.sub.3                            "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.18 H.sub.37                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.3 H.sub.7                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.8 H.sub.17                  "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.12 H.sub.25                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.3 H.sub.6 OC.sub.16 H.sub.33                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.9                   "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2                                    H.sub.5                                              "    "    "    "    --COOR.sub.4                                                                         "  (19)      84-86                                   "    "    "    "    --CN  --C.sub.4 H.sub.8 OC.sub.4 H.sub.8 OC.sub.4                                    H.sub.9                                              "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --CN  --C.sub.8 H.sub.16 OC.sub.8 H.sub.17                 "    "    "    "    --COOR.sub.4                                                                         "                                                    "    "    "    "    --H   --CH.sub.3                                           --CH.sub.3                                                                          "    "    "    --COOR.sub.4                                                                         --C.sub.18 H.sub.37 (IV)                                                                    87-90                                   t.butyl                                                                             "    "    "    --CN  --CH.sub.2 CH=CH.sub.2                               "    "    "    "    --COOR.sub.4                                                                         "                                                    i.propyl                                                                            i.propyl                                                                            i.propyl                                                                            i.propyl                                                                            --COOR.sub.4                                                                         --C.sub.2 H.sub.4 SC.sub.12 H.sub.25                                                        72                                      s.butyl                                                                             s.butyl                                                                             s.butyl                                                                             s.butyl                                                                             --COOR.sub.4                                                                         --C.sub.18 H.sub. 37                                                                        50                                      --CH.sub.3                                                                          t.butyl                                                                             i.propyl                                                                            i.propyl                                                                            --COOR.sub.4                                                                         --C.sub.18 H.sub.37                                                                         90-93                                   __________________________________________________________________________

The dialkylbenzyl carboxylic acid esters of the invention are good stabilizers against deterioration by oxygen, light and heat of polymers such as polyolefins, polyamides, shock resistant polystyrene, ABS resins (copolymers of acrylonitrile, butadiene, and styrene), MBS resins (copolymers of methacrylic acid esters, butadiene, and styrene), homopolymers and copolymers of vinyl chloride, and similar resins.

Good stabilizing effects are particularly obtained with compounds of the following formulae ##SPC12## ##SPC13##

and mixtures of these compounds with each other or with sulfur containing stabilizers such as bis esters of thiodipropionic acid. We prefer to use compounds in which the R₄ group contains more than 6 carbon atoms and oxygen or sulfur in form of an ether or thioether group. Good stabilizers are also mixtures of said compounds with the compound corresponding to the formula ##SPC14##

The novel stabilizers have excellent compatibility with the resins and, due to their low volatility, remain effective even after prolonged thermal exposure of the resin. Generally, they are employed in an amount of 0.01 to 10 percent by weight of the resin. As shown in the examples, they are superior to the esters described e.g. in the German Pat. (DAS) No. 1,201,349 and to the frequently proposed thiobisphenols.

The following examples are given to illustrate the invention but it is to be understood that the resins and stabilizers employed may be substituted by similar compounds and that the scope of the invention is not to be limited to the specific compounds and resins. All parts are by weight, unless indicated otherwise.

EXAMPLE 5 Stabilization of Polypropylene

Four types of unstabilized polypropylene powder, A, B, C, and D were used. For the tests reported in Table II, 100 parts of polypropylene, containing the amounts of stabilizer as indicated, were hot milled at 180°C. for 10 minutes and sheeted off.

The films were piled up and pressed under a pressure of 200 atm. at 210°C.

The obtained plates of 1 mm thickness were cut into 5 strips which were aged in a circulating air oven at 150°C, and the beginning of brittleness was noted.

                                      TABLE II                                     __________________________________________________________________________     Polypropylene                                                                              Stabilizer        Days before                                                                    begin of                                                                       oxidative                                                                      degradation                                      __________________________________________________________________________     A       0.5 parts 4,4'-thio-bis-(6-tert.                                                                     11                                                           butyl-m-cresol)                                                    A       0.5 parts β-(3,5-di-tert.butyl-                                               4-hydroxyphenyl)-propionic                                                                       46                                                           acid stearyl ester                                                 A       0.5 parts Stabilizer I                                                                               75                                               A       0.5 parts Stabilizer V*)                                                                             72                                               B       0.3 parts 4,4-thio-bis-(6-tert.                                                    butyl-m-cresol)   17                                               B       0.3 parts β-(3,5-di-tert.butyl-4-                                             hydroxyphenyl)-propionic acid                                                                    20                                                           stearyl ester                                                      B       0.1 parts β-(3,5-di-tert.-butyl-4-                                            hydroxyphenyl)-propionic acid                                                                    24                                                           stearyl ester + 0.2 parts                                                      DLTDP**)                                                           B       0.3 parts Stabilizer II                                                                              43                                               C       0.3 parts 4,4-thio-bis-(6-tert.                                                    butyl-m-cresol)   17                                               C       0.3 parts (3-methyl-5-tert.-butyl-4-                                               hydroxy-benzyl)-malonic acid-                                                                    19                                                           distearylester                                                     C       0.3 parts β-(3,5-di-tert.butyl-4-                                             hydroxy-phenyl)-propionic acid                                                                   20                                                           stearylester                                                       C       0.3 parts Stabilizer I                                                                               19                                               C       0.3 parts Stabilizer 22                                                                              39                                               C       0.3 parts Stabilizer III                                                                             49                                               C       0.3 parts Stabilizer 24                                                                              40                                               D       0.3 parts β-(3,5-di-tert.butyl-4-                                             hydroxy-phenyl)-propionic acid                                                                   74                                                           stearylester                                                       D       0.3 parts Stabilizer 11                                                                              77                                               D       0.3 parts Stabilizer 12                                                                              78                                               D       0.3 parts Stabilizer II                                                                              111                                              D       0.3 parts Stabilizer 23                                                                              111                                              __________________________________________________________________________      **)dilaurylthiodipropionate                                                    *)a mixture of 10 parts of Stabilizer I and 90 parts of                        (4-hydroxy-3-methyl-5-tert.butylbenzyl)-malonic acid distearylester            (corresponding to formula II).                                           

Using three different types of unstabilized polypropylene powder, the tests reported in Table III were conducted according to the procedure of Example 5 for Table II except the aging temperature was 140°C.

                                      TABLE III                                    __________________________________________________________________________     Polypropylene                                                                          Stabilizer            Days before                                                                    begin of                                                                       oxidative                                                                      degradation                                      __________________________________________________________________________     E              without stabilizer                                                                            1                                                E       0.2 parts                                                                             2,6-di-tert.butyl-p-cresol                                                                    1                                                E       0.2 parts                                                                             Stabilizer 6   6                                                E       0.2 parts                                                                             Stabilizer 7   7                                                F       0.2 parts                                                                             (3-methyl-5-tert.butyl-4-                                                                     32                                                              hydroxy-benzyl)-malonic                                                        acid-distearyl ester                                            F       0.2 parts                                                                             Stabilizer 20  32                                               F       0.2 parts                                                                             Stabilizer 21  65                                               F       0.1 parts                                                                             (3-methyl-5-tert.butyl-4-                                                                     3                                                               hydroxy-benzyl)-malonic                                                        acid-distearylester                                             F       0.1 parts                                                                             Stabilizer 8   6                                                F       0.1 parts                                                                             Stabilizer 9   4                                                F       0.1 parts                                                                             Stabilizer 10  14                                               F       0.1 parts                                                                             Stabilizer 14  9                                                F       0.1 parts                                                                             Stabilizer 18  6                                                F       0.1 parts                                                                             Stabilizer 20  21                                               F       0.1 parts                                                                             Stabilizer 21  13                                               G              none           1                                                G       0.1 parts                                                                             2,6-di-tert.butyl-p-cresol                                                                    1                                                G       0.1 parts                                                                             (3-methyl-5-tert.butyl-4-                                                                     3                                                               hydroxy-benzyl)-malonic                                                        acid-distearylester                                             G       0.1 parts                                                                             β-(3,5-di-tert.butyl-4-                                                                  9                                                               hydroxy-phenyl)-propionic                                                      acid stearylester                                               G       0.1 parts                                                                             Stabilizer 12  9                                                G       0.1 parts                                                                             Stabilizer 15  40                                               G       0.1 parts                                                                             Stabilizer 16  23                                               G       0.1 parts                                                                             Stabilizer 17  44                                               G       0.1 parts                                                                             Stabilizer 19  22                                               G       0.1 parts                                                                             Stabilizer 21  36                                               __________________________________________________________________________

An unstabilized polypropylene powder was tested using the procedure of Example 5 for Table II, except the plates were subjected to outdoor exposure.

                                      TABLE IV                                     __________________________________________________________________________     Stabilizer                   Days before                                                                    beginning of                                                                   oxidative                                                                      degradation                                       __________________________________________________________________________            none                  37                                                0.2 parts                                                                             (3,5-di-methyl-4-hydroxy-benzyl)-thio-                                                               90                                                       glycolic acid stearylester                                              0.2 parts                                                                             β-(3,5-di-tert.butyl-4-hydroxy-phenyl)                                                          127                                               propionic acid stearylester                                                    0.2 parts                                                                             (3-methyl-5-tert.butyl-4-hydroxy-benzyl)-                                                            127                                                      malonic acid-distearylester                                             0.2 parts                                                                             Stabilizer 6          127                                               0.2 parts                                                                             Stabilizer 7          250                                               __________________________________________________________________________

EXAMPLE 6 Stabilization of Low Pressure Polyethylene

20 G each of low pressure polyethylene and 20 mg of the stabilizer listed in Table V were processes on a plastograph at 220°C and 30 RPM and the time was noted until the torque dropped, indicating degradation of the polymer.

                  TABLE V                                                          ______________________________________                                         Stabilizer             Torque decreased                                                               after                                                   ______________________________________                                         β-(3,5-di-tert.butyl-4-hydroxyphenyl)-                                                            40 ± 2 minutes                                      propionic acid stearyl ester                                                   β-(3,5-di-tert.butyl-4-hydroxyphenyl)-                                                           135 + 2 minutes                                         propionic acid stearyl ester + 20 mg                                           DLTDP                                                                          Stabilizer III         140 + 2 minutes                                         ______________________________________                                    

The table shows the superiority of the stabilizer of the invention over the known stabilizers of similar type.

100 Parts of low pressure polyethylene, containing 0.02 parts of stabilizer as indicated in Table VI were hot milled at 170° for 10 minutes and sheeted off. The films were piled up and pressed under a pressure of 200 atm. at 180°C.

The plates obtained were of 1mm thickness. These were cut into 5 strips which were aged in a circulating air oven at 130°C, and the beginning of brittleness was noted. The results are reported in Table VI.

                  TABLE VI                                                         ______________________________________                                         Stabilizer              became brittle                                                                 after days                                             ______________________________________                                         none                    1                                                      2,6-di-tert.butyl-p-cresol                                                                             1                                                      (3-methyl-5-tert.butyl-4-hydroxy-benzyl)-                                      malonic acid-distearylester                                                                            2                                                      Stabilizer 13           50                                                     Stabilizer 15           50                                                     Stabilizer 16           59                                                     Stabilizer 17           43                                                     Stabilizer 19           57                                                     ______________________________________                                    

EXAMPLE 7 Stabilization of High Pressure Polyethylene

Samples of 100 g of high pressure polyethylene containing the stabilizers reported in Table VII were stored in a drying cabinet at 150°C, and the times to yellow discoloration were determined.

                                      TABLE VII                                    __________________________________________________________________________     Stabilizer               Hours to beginning                                                             of discoloration                                      __________________________________________________________________________     0.01 parts                                                                            2,6-di-tert.butyl-p-cresol +                                                                     20                                                    0.01 parts                                                                            DLTDP                                                                   0.02 parts                                                                            β-(3,5-di-tert.butyl-4-hydroxy-                                                             26                                                           phenyl)-propionic acid stearyl                                                 ester                                                                   0.02 parts                                                                            Stabilizer IV     28                                                    0.02 parts                                                                            Stabilizer II     35                                                    __________________________________________________________________________

EXAMPLE 8 Stabilization of Polyamide

100 parts of polyamide containing 1 part of the stabilizers listed in Table VIII were processed on an extruder at 250°C to plates which were divided into 5 strips and subjected to accelerated aging in a drying cabinet at 250°C. The stabilizing effect was determined by the brittleness of the samples.

                                      TABLE VIII                                   __________________________________________________________________________     Stabilizer               became brittle                                                                 after days                                            __________________________________________________________________________     1 part                                                                               4,4'-thio-bis-(6-tert.butyl-m-cresol)                                                               17                                                  1 part                                                                               β-(3,5-di-tert.butyl-4-hydroxyphenyl)                                     propionic acid stearyl ester                                                                        13                                                  0.5 parts                                                                            copper-II-acetate                                                        0.5 parts                                                                            potassium iodide     19                                                  0.5 parts                                                                            stabilizer I                                                             0.5 parts                                                                            tris-nonylphenylphosphite                                                                           20                                                  0.5 parts                                                                            stabilizer V                                                             0.5 parts                                                                            tris-nonylphenylphosphite                                                                           22                                                  __________________________________________________________________________

The table shows that the stabilizers of the invention exceed the effectiveness of known antioxidants. An addition of organic phosphite improves further the initial color of the extruded plates.

EXAMPLE 9 Stabilization of an ABS Resin

All the tests hereinafter set forth in Table IX were made with the same ABS polymer which had the approximate composition by weight of 5% acrylonitrile, 15% butadiene, and 80% styrene. Test samples were prepared by hot milling at about 160°C for 10 minutes compositions containing 100 parts of the ABS resin, 1 part of a lubricant (1,2-bis-stearoyl amino ether) and 0.5 parts of the stabilizer. The obtained films were pressed under a pressure of 200 atm. and a temperature of 180°C to plates of 1 mm thickness, which were cut to strips and placed in a drying cabinet at a temperature of 110°C for accelerated aging. The stabilizing efficiency was measured by the change of color and brittleness of the strips. The following results were obtained.

                                      TABLE IX                                     __________________________________________________________________________     Stabilizer           color after                                                                           brittle after                                                           50 days                                                                               days                                               __________________________________________________________________________     4,4'-thio-bis-(6-tert.butyl-m-cresol)                                                               brown  40                                                 β-(3,5-di-tert.butyl-4-hydroxy-phenyl-                                    propionic acid stearyl ester                                                                        light yellow                                                                          36                                                 Stabilizer II        pale yellow                                                                           43                                                 __________________________________________________________________________

EXAMPLE 10 Stabilization of an MBS Resin

The tests listed in Table X were made with the same MBS polymer which had the approximate composition by weight of 16% methacrylic acid ester, 80% butadiene, and 4% styrene.

Test samples were prepared by hot milling at 170°C for 10 minutes the resin compositions containing the stabilizer and pressing the obtained films in a platen press under a pressure of 200 atm. at a temperature of 190°C to plates of 1 mm thickness which were cut into 5 strips and aged in a drying cabinet at 90°C.

The stabilizing effect was determined by the color changes and brittleness of the strips. The following results were obtained.

                                      TABLE X                                      __________________________________________________________________________     Stabilizer          Color    Brittle after                                                         after 20 days                                                                           days                                              __________________________________________________________________________     0.5 parts 4,4'-thio-bis-(6-tert.                                                                   brown    38                                                    butyl-m-cresol)                                                            0.25                                                                               parts 2,5-di-tert.butyl-p-                                                     cresol +        yellow   57                                                0.25                                                                               parts tris-nonylphenylphos-                                                    phite                                                                      0.25                                                                               parts stabilizer I +                                                                           light yellow                                                                            65                                                0.25                                                                               parts tris-nonylphenyl-                                                        phosphite                                                                  0.25                                                                               parts stabilizer V +                                                                           light yellow                                                                            62                                                0.25                                                                               parts tris-nonylphenyl-                                                        phosphite                                                                  __________________________________________________________________________

EXAMPLE 11 Stabilization of Impact Resistant Polystyrene

The impact resistant polystyrene was a blend of 88 parts of polystyrene and 12 parts of a butadiene-styrene copolymer which contained as stabilizer 1.2% of tris-nonylphenyl phosphite. 12 g each of said copolymer were plasticized on a laboratory roller mill at 175°C, then 0.15 g of the stabilizer listed in Table XI, and subsequently 88 g of polystyrene were added, and the blends were hot milled at 175°C for 10 minutes and at 180°C and 200 atmospheres pressed to plates which were cut into 5 strips and stored in a drying cabinet at 85°C. The stabilizing effect was determined by the time of beginning brittleness of the samples.

                  TABLE XI                                                         ______________________________________                                         STABILIZER         Color      Brittle after                                                       after 10 days                                                                             days                                             ______________________________________                                         4,4'-thio-bis-(6-tert.butyl-m-                                                                    deep yellow                                                                               25                                               cresol)                                                                        β-(3,5-di-tert.-butyl-4-hydroxy-                                          phenyl)-propionic acid stearyl                                                                    yellow     17                                               ester                                                                          Stabilizer II      pale yellow                                                                               25                                               ______________________________________                                     

What is claimed is:
 1. A compound corresponding to the formula ##SPC15##wherein R₁, R₂, R₅ and R₆ are alkyl groups having 1 to 6 carbon atoms and R₄ is selected from the group consisting of alkyl, straight chain alkenyl, sulfur interrupted alkyl, oxygen interrupted alkyl and aralkyl having up to 20 carbon atoms.
 2. A compound of claim 1 wherein R₄ is selected from the group consisting of --C₂ H₄ SC₂ H₅, --C₂ H₄ SC₃ H₇, --C₂ H₄ SCH(CH₃)₂, --C₂ H₄ SC₄ H₉, --C₂ H₄ SC₆ H₁₃, --C₂ H₄ SC₈ H₁₇, --C₂ H₄ SCH₂ CH(C₂ H₅) (CH₂)₃ CH₃, --C₂ H₄ SC₁₂ H₂₅, --C₂ H₄ SC₁₆ H₃₃, --C₃ H₆ SC₃ H₇, --C₃ H₆ SC₈ H₁₇, --C₃ H₆ SC₁₂ H₂₅, --C₃ H₆ SC₁₆ H₃₃, --C₄ H₈ SC₄ H₉, --C₂ H₄ SC₂ H₄ SC₂ H₅, --C₄ H₈ SC₄ H₈ SC₄ H₉, --C₈ H₁₆ SC₈ H₁₇, and --C₂ H₄ SC₁₈ H₃₇.
 3. A compound of claim 1 wherein R₄ is selected from the group consisting of --C₂ H₄ OC₂ H₅, --C₂ H₄ OC₃ H₇, --C₂ H₄ OCH(CH₃)₂, --C₂ H₄ OC₄ H₉, --C₂ H₄ OC₆ H₁₃, --C₂ H₄ OC₈ H₁₇, --C₂ H₄ OCH₂ CH(C₂ H₅) (CH₂)₃ CH₃ --C₂ H₄ OC₁₂ H₂₅, --C₂ H₄ OC₁₆ H₃₃, --C₃ H₆ OC₃ H₇, --C₃ H₆ OC₈ H₁₇, --C₃ H₆ OC₁₂ H₂₅, --C₃ H₆ OC₁₆ H₃₃, --C₄ H₈ OC₄ H₉, --C₂ H₄ OC₂ H₄ OC₂ H₅, --C₄ H₈ OC₄ H₈ OC₄ H₉, --C.sub. 8 H₁₆ OC₈ H₁₇ and --C₂ H₄ OC₁₈ H₃₇.
 4. A compound of claim 1 wherein R₄ is selected from the group consisting of --CH₃, --C₂ H₅, --CH₂ (CH₂)₂, --C₄ H₉, --C(CH₃)₃, --CH₂ CH(CH₃)₂, --C₆ H₁₃, --C₈ H₁₇, --CH₂ CH(C₂ H₅) (CH₂)₃ CH₃, --C₁₂ H₂₅, --C₂₀ H₄₁, ##SPC16##
 5. A compound of claim 3 wherein R₁, R₂, R₅ and R₆ are tert. butyl.
 6. A process of preparing a compound of claim 1 which comprises reacting, in the presence of an alkali metal and an anhydrous inert organic solvent, (a) one mole of ##SPC17##and (b) one mole of ##SPC18## with one mole of NCCH₂ COOR₄ wherein X is halogen.
 7. A process according to claim 6 wherein the inert solvent is selected from the groups of aromatic hydrocarbons, aliphatic hydrocarbons and glycol ethers. 